1,721,046 research outputs found
Performance at cellar level of selected autochthonous and commercial Saccharomyces cerevisiae strains during fermentation of “Primitivo di Matera” grape variety
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Development of a new brewing strain with improved aroma through hybridization and UV mutagenesis
No full textYeasts are fundamental in beer production, influencing fermentation, flavor, and stability. To meet consumer demand, we developed a novel, GMO-free yeast hybrid between a sourdough strain of Saccharomyces cerevisiae and a cryotolerant S. eubayanus x S. bayanus via spore-to-spore hybridization. Microfermentations showed improved brewing traits in one hybrid but also the undesired Phenolic Off-Flavor (POF+) phenotype, caused by the conversion of ferulic acid into 4-vinyl guaiacol (4VG). To eliminate this trait, we applied UV mutagenesis, optimizing irradiation conditions (50 cm distance, 30 s exposure) to achieve 8-22% mortality. Nystatin treatment, which selects slow-growing mutants, reduced the mutation success rate (13.3% without vs. 0.4% with nystatin). Mutants were screened on YPDA with 4 mM ferulic acid and analyzed via Ferulic Acid Conversion Index (FACI) and Cinnamic Acid Sensitivity Index (CASI). POF- candidates exhibited low FACI and high CASI values, confirming reduced 4VG production. Further microfermentations confirmed that selected mutants retained improved brewing traits without the POF+ phenotype. This study demonstrates that hybridization combined with UV mutagenesis is an effective, GMO-free strategy for developing superior brewing yeasts
Comparative study of Saccharomyces cerevisiae indigenous wine strains to identify potential marker genes involved in desiccation stress resistance
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Unraveling Lactobacillus helveticus species inhabiting cultivable fraction of natural whey starter: a genotype and phenotype-based study
No full textThe lactic acid bacterium (LAB) Lactobacillus helveticus is a key player in thermophilic dairy fermentation. LAB also inhabit the human gut, which has often been exploited as a reservoir of potential novel probiotics. We analyzed the cultivable fraction of 12 natural whey starters (NWS) sampled in 2 different sampling times through DNA barcoding and genotypic approach. Twenty-five candidates were evaluated for tolerance to bile acids (BA), low pH, and lysozyme as probiotic traits.
Pentaplex-PCR and 16S-ARDRA analyses were used as DNA barcoding techniques. (GTG)5 REP-PCR was carried out to estimate the intra-species diversity (Simpson’s index) and dereplicate the clones library. BA tolerance and pH tolerance were assessed by cultivating strains in the presence bile salt mixture (0.05%, 0.3%, 0.6%, and 1%), and at pH of 3.5, 4.5, and 5.4, respectively. Lysozyme (0.1 mg/mL) was used to test lysozyme tolerance.
Inter-species diversity was >0.9 Simpson’s index for NWS enriched in L. helveticus (type-H), while was slightly lower in NWS enriched in L. delbrueckii (type-H). Huge phenotypic diversity was found within a pool of 25 genotypically unique strains. Two candidates showed the best growth response to all three stresses tested
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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